brace



atentecl Jan. 31, 1939 NITE!) STABS Matt PATENT FFiE International Engineering Corporation,

Chi-

cago, Ill., a corporation of Illinois Application March 20, 1936, Serial No. 69,879

1 Claim.

This invention relates to pumps, and is illustrated as embodied in a pump used as an air compressor. An object of the invention is to provide a simple structure of a rotary type, capai ble of building up higher pressures than a centrifugal pump and yet free from reciprocating parts such as pistons or vanes.

Preferably a liquid is used as the pressure medium of the pump, it being usually arranged in a casing against the outer wall of which it is held by centrifugal force derived irom a rotor turning within the casing. The liquid does not iill the casing, and, when it is so thrown outwardly by the rotor, a space about the axis oi the casl ing is left free of liquid. The rotor divides this space into intake and outlet portions, provided with corresponding passages or with other intake and outlet means respectively.

According to an important feature of the invention, the rotor is provided peripherally with a passage, having an intake and an outlet at its opposite ends, and shown as formed by a hollow helix mounted on the periphery of the rotor and driven by the rotor about an axis offset from the axis of the casing. Thus as the rotor is turned,

for example by a motor outside the casing having a drive shaft extending into the casing and there drivably engaging the rotor, the intake and outlet ends of the passage are periodically placed 3o in communication respectively withv the inlet and outlet portions of the central space. Preferably the rotor has means, such as radial vanes, for causing the desired centrifugal action of the sealing liquid.

If desired, the above-described helix can be carried several times around the rotor, decreasing in cross-sectional size toward the outlet end, thereby giving the effect of multistage compression.

The above and other objects and features of the invention, including various novel combinations of parts and desirable particular constructions, will be apparent from the following description of the illustrative embodiments shown in the accompanying drawings, in which:

Figure l is a view of one embodiment of the compressor in vertical section, with the associated motor shown in side eievationgf Figure 2 is an end elevation of the rotor;

5() Figure 3 is an elevation of the rotor looking from the right toward the leit in Figure 2;

Figure 4 is a view corresponding to Figure l, but showing a different modification; v

Figure 5 is a side elevation of the rotor in Figure 4; and

Figure 6 is an end elevation of the rotor in Figure 4.

In the embodiment of Figures l to 3, the compressor comprises a casing I0 having at one end an intake device I2 (either open to the atmos- 5 phere or suitably connected with some other source of gas to be compressed), and having at its other end an outlet device I4 adapted to be connected by a suitable conduit with any desired apparatus in which the compressed gas is to be 10 used.

The intake device I2 (unless it is to be open to the atmosphere) is provided with a suitable stuing box i6 for a drive shaft I8, shown journaled in ball bearings 20 in the end walls of the l5 casing I0. The shaft IB is arranged to be driven, through any suitable coupling 22, by means such as a motor 24. The devices I2 and I4 communicate with the interior of the casing lli through suitable openings 26. 20

The shaft I8 is not coaxial with respect to the casing I0, but is eccentric with respect thereto, being shown above the casing axis. Inside the casing I0, the shaft I8 has rotatably mounted thereon a rotor comprising, as illustrated, a hol- 25 low body 28 keyed to the shaft to be rotatably driven thereby. The body 28 has secured about its periphery two approximately parallel flanges or webs 38 and 32, formed to define a hollow helix when sealed as described below, thereby defining 30 a helical passage peripherally of the rotor.

The casing I0 contains a quantity of sealing liquid 34, selected not to react with the gas being compressed, and which in most cases may be water. The flanges 38 and 32 carry means, shown 35 as radial vanes 36 secured between the anges but with spaces 38 left between them and the periphery of the rotor body 28, for carrying the liquid 34 around with the rotor and imparting to it sufficient centrifugal force to hold it out 40 against the casing I0 in a zone of liquid whose central axis is the axis of the casing Ill, some distance below the rotor axis.

Thus the liquid 34 iills the entire space between the flanges 30 and 32 at the top of the casing, b-ut merely seals across their edges at the bottom of the casing, as appears in Figure 1. As shown in Figure 3, the trailing end of the flange overlaps (and may be secured to) the forward end' of the flange 32. Thus, since the liquid 38 seals the edges of the anges all the way around, the rotor itself forms a partition separating an intake space 40 in the right end of the casing (in communication with the intake device I2) from 55 an outlet space 42 in the left end of the casing (in communication with the outlet device I4).

The only way the gas can go from the space t@ to the space 42 is through the helical passage between the anges 3U and 32. The liquid between the anges at the top of the casing serves as the equivalent of a compressor piston, and as the rotor turns it forces the gas along the passage and through the openings 38 to the outlet space 42.

The embodiment of Figures 4 to 6 differs from that described above in that the rotor includes a somewhat longer driven body |28, to the periphery of which is secured a single helically arranged flange |38 which` passes a number of times around the rotor with a decreasing spacing. Vanes |36 (formed with openings |38 to permit the passage of the compressed gas) are secured 'to the flange |36 at intervals to impart the desired centrifugal force to the liquid 34.

In this embodiment, the successive charges of gas being compressed are moved along the lower part of the rotor, parallel to the rotor axis, in the helical passage defined between the successive turns of the flange |30, during several revolutions of the rotor. As the cross-sectional size of this passage decreases toward the outlet end, this gives increased compression, and provides what may be regarded as the equivalent of a multi-stage compressor.

While two illustrative embodiments have been described in detail, it is not my intention to limit the scope of the invention to those particular embodiments, or otherwise than by the terms of the appended claim.

I claim:

A pump having a cylindrical casing containing a liquid and formed with inlet openings in one end and outlet openings in the other end, a rotor comprising a hollow cylindrical body having on its periphery spaced approximately parallel webs and radial vanes secured between said webs and spaced outwardly from the surface of said body to leave a passage between the vanes and said body, the said rotor being seated eccentrically to the axis of the casing acting centrifugally on the liquid to force fluid from the inlet to the outlet openings, and inlet and outlet devices mounted on the ends of the casing over said openings and having respectively inlet and outlet means above said openings.

KEMPER P. BRACE. 

